1. Field of the Invention
The invention relates to a quick connect coupler to mate with either the high-side or low-side of the service port of a refrigeration system.
2. Description of Related Art
Refrigeration is a special aspect of heat transfer and involves the production and utilization of below-atmospheric temperatures. In a conventional refrigeration system, a refrigerant fluid is circulated through a closed system comprising a compressor, a condenser, expansion valves and an evaporator. Continuous recirculation of the cycle fluid or the refrigerant transports the heat energy from a low-temperature to a high-temperature level, thus providing the cooling power that can be used for applications such as air conditioning or refrigeration. During the transportation process, the refrigerant fluid changes its state from fluid to gas and then from gas back to fluid.
Freon is the most commonly used refrigerant fluid. According to the ANSI code B79.1-1968, refrigerant fluids are designated by numbers, such as, for example, Freon 12, R-12, or Jenetron 12. The chemical composition of Freon 12 or R-12 refrigerant fluid is dichlorodifluoromethane (CCl.sub.2 F.sub.2) Unfortunately, for a variety of reasons, Freon gas can leak into the atmosphere. Leaking Freon gas is believed to be a cause of ozone depletion and, therefore, is considered to be an environmental hazard, which has been implicated in the so-called "green-house" effect. New regulations of the U.S. Environmental Protection Agency mandate the use of a refrigerant known as R-134A, or HFC-134, in which the dichloride is replaced by hydrogen in the dichlorodifluoromethane. Even though this new refrigerant is believed to minimize ozone depletion, it is still not permitted to be released into the atmosphere. Rather, it is required to be recycled in a closed system known as a recycling machine.
The refrigerant fluid is typically removed from a conventional heat transfer device by connecting the recycling machine to the high or low service port directly before or after the compressor stage of a refrigeration system. It is important that the connecting device or coupler seals the refrigeration service port quickly and efficiently in order to eliminate the leakage of refrigerant to the atmosphere. Conventional fittings, adapters and couplings have been used for connecting and disconnecting recycling machines to the tubular high or low-side service ports of air conditioning systems. In particular, conventional couplers and ports are commonly used for R-12 refrigerant systems. Recently the Society of Automotive Engineers (SAE), the Environmental Protection Agency (EPA) and automotive manufacturers have recommended that the high and low-side service ports of automotive air conditioners be provided with special quick connect/disconnect ports that do not require threads or screws. The purpose of this requirement is two-fold. First, it provides a quicker couple with better and safer sealing characteristics. Second, it prevents cross contamination of the two refrigerants (R-12 and R-134A). In order to comply with this requirement, manufacturers have begun to make couplings and fittings to comply with the requirements of the SAE, EPA and auto manufacturers. Unfortunately, many of these new couplers are bulky and large making them difficult to manipulate in small and crowded locations. Also, they take a significant amount of time to couple and uncouple and frequently require the screwing and unscrewing of a valve.
One major application of the new refrigerant, R-134A, is in automotive air conditioning systems as required by the EPA. Automotive manufacturers have begun to implement the use of the R-134A refrigerant and have provided a rather small space in the engine compartment for connecting the coupler to the high-side or low-side service port of the air conditioning unit. Conventional fittings and adapters that are available in the marketplace are difficult to use o all automotive applications since the maneuvering space within the engine compartment is so small.
In view of the foregoing, it is clear that there is a need for a coupling system that will quickly seal, snap in place and lock with respect to a service port of an automotive air conditioning system, either on the high-side or the low-side. It is also important that the coupler provide locking mechanism that prevents it from blowing off during installation or removal. That is to say, the invention should not permit a burst of air conditioning refrigerant to blow out as it is being connected or disconnected for environmental and safety reasons.
The conventional manner of connecting two mating tubes carrying fluid or gases usually involves the use of screws or clamps. Many fittings and connectors have been available on the market and used for specific applications. Unfortunately, they generally do not provide all of the necessary features in one unit, namely: quick connection; safe sealing; locking; safety; small size, and easy to use.
Automotive manufacturers such as Mercedes-Benz do provide adapters that can couple with the service port of an automotive air conditioner, however, with the Mercedes-Benz adaptor, it takes time to unscrew the valve and it is relatively heavy and bulky. Other manufacturers are also believed to have fabricated adapters that are relatively large and time consuming to manipulate.
Some prior art patents discuss devices that address one or two of the needs solved by the present invention but do not appear to address them all in a satisfactory way. Note, for example, the teachings in U.S. Pat. Nos. 4,667,925; 4,756,558; 4,913,467; 5,046,523 and 5,069,424.
It was in the context of the foregoing prior art that the present invention arose.